Water Policy 2026: Balancing Growth, Costs & the Environment

Introduction & Author’s Note

In my role as the Executive Director of Sustainable San Mateo County (SSMC), I often find myself at the intersection of complex regional debates. I am not a water management expert or a hydrologist; rather, my goal in writing this article is to help our community navigate the interconnected challenges of environmental health, economic vitality and social equity. On February 18, I attended a meeting of the San Mateo County Resource Management and Climate Protection Committee (part of the City/County Association of Governments, or C/CAG) to listen to a critical debate that touches all three of those pillars.

This article was originally published on LinkedIn.

Why Water Policy Matters

Imagine a small business owner in San Mateo County, perhaps running a local nursery or a laundromat. They rely on a steady flow of water to keep their operations running, but they are increasingly concerned about the rising costs on their monthly bills. Now, imagine a conservationist watching salmon populations in the Tuolumne River reach critical lows.

While these two perspectives are often framed as a conflict between “the economy vs. the environment,” they share a common thread: both are looking for a system that is sustainable and predictable. High costs and declining fish populations are both signals that our traditional water management strategies are facing unprecedented pressure from climate change and aging infrastructure.

For the city councils and water districts across San Mateo County, this shared challenge is coming to a head right now. By July 2026, every urban water supplier must submit an updated Urban Water Management Plan (UWMP). These plans are the primary tool local leaders use to balance their fiduciary responsibility to keep water available and affordable with their environmental duty to protect our natural resources. As we look toward this deadline, it is vital that we move past “us vs. them” narratives and look at the data driving our future.

The Regional Context: BAWSCA and the Hetch Hetchy System

The Bay Area Water Supply and Conservation Agency (BAWSCA) represents 26 wholesale customers, including cities and water districts in San Mateo, Santa Clara and Alameda counties. These agencies provide water to over 1.8 million residents and 40,000 commercial, industrial and institutional accounts. A significant portion of this water comes from the Hetch Hetchy Regional Water System, which draws from the Tuolumne River in the Sierra Nevada. For many member agencies, including several in San Mateo County, the Hetch Hetchy system accounts for over 60% of their total water supply, with some relying on it for 100% of their needs.

BAWSCA’s primary goal is to ensure a reliable supply of high-quality water at a fair price. To achieve this, they use “design drought” scenarios—conservative estimates that project what would happen during a repeat of the worst droughts on record. These projections help water agencies plan for infrastructure and conservation measures to ensure the taps never run dry.

The Economic Paradox: Why Bills Rise When We Conserve

While BAWSCA focuses on the engineering of a reliable supply, the local financial reality for the consumer often feels counterintuitive. There is a frustrating paradox in water management that many residents find difficult to swallow: the more we conserve, the more expensive each gallon becomes. As C/CAG Executive Director Sean Charpentier points out, water systems are defined by high fixed costs. Whether a pipe carries ten gallons or a hundred, the cost to maintain that pipe, the pumps and the treatment facilities remains the same.

When a drought hits and we all do our part to cut back, the water agency still has to pay its staff and maintain thousands of miles of infrastructure. Because they are selling fewer “units” of water, the price per unit must rise to cover those fixed operational costs. This is the logic behind the “drought surcharges” that often appear on our bills just as we are trying to be most responsible. For local jurisdictions, there is a fiduciary responsibility to keep these costs balanced, even when the sky is dry.

The “Demand Hardening” Trap and the 50-Gallon Limit

While we often hear calls for more conservation, we are running into a technical challenge known as “demand hardening.” Over the last few decades, San Mateo County residents have been leaders in efficiency. We have already replaced our old toilets, installed low-flow showerheads and torn out thirsty lawns.

According to Burlingame Councilmember Donna Colson, this means there is very little “low-hanging fruit” left to cut. In a severe “design drought” scenario, agencies like BAWSCA have to model extreme outcomes. In such a case, residents could be restricted to as little as 50 gallons per person, per day. To put that in perspective, a single eight-minute shower uses about 17 gallons and a single load of laundry uses 15 to 30. When our efficiency is already “baked into the system,” further cuts aren’t just about shorter showers—they require fundamental changes to how we live.

The Environmental Challenge: The Yosemite Rivers Alliance Perspective

The Yosemite Rivers Alliance (YRA) offers a different perspective, focusing on the health of the Tuolumne River and the San Francisco Bay Delta. According to Peter Drekmeier of YRA, the Bay Delta is an “ecosystem in crisis.” The Tuolumne River’s salmon counts have seen a dramatic decline, and salmon are considered a “keystone species” that support over 100 other species throughout their life cycles.

The YRA argues that current and proposed water release practices are insufficient. They point out that fish habitat quality is primarily controlled by water flows, and low flows lead to higher water temperatures, which can be fatal for native fish like salmon and trout. Furthermore, low flows and warm water create ideal conditions for non-native predators and toxic algae blooms in the Delta.

The Keystone of the Coast: Why Salmon Matter

While we often think of water in terms of gallons for our homes, it is also the literal lifeblood of a biological infrastructure that supports the entire West Coast. Central to this is the Chinook salmon. Ecologists view them as a keystone species—the biological glue that holds an entire ecosystem together.

The importance of protecting their habitat on the Tuolumne River goes far beyond the fish themselves:

• The Nutrient Cycle: Salmon are unique “nutrient couriers.” They spend their lives gathering nitrogen and phosphorus from the vast Pacific Ocean and then carry those nutrients hundreds of miles inland to the high Sierra. When they spawn and die, their remains fertilize the entire watershed. Researchers have found marine-derived nutrients in the needles of trees and the bodies of over 100 species—from bears and eagles to the insects that feed forest birds. If the salmon disappear, the “fertilizer” for our forests disappears with them.
• The Temperature Trigger: Salmon are cold-water specialists. Habitat restoration, such as adding spawning gravel, is often discussed as a solution, but it is secondary to water flow. If the river flow is too low, the sun heats the water above 68°F, which is lethal for salmon eggs. Without sufficient, cold “push” from the upstream dams, even the best-constructed habitat becomes a graveyard.
• Floodplain “Nurseries”: High water flows are necessary to push the river over its banks and into the floodplains. These shallow, slow-moving waters act as nurseries where juvenile salmon can hide from predators and find enough food to grow large enough for their trek to the sea. Without these seasonal floods, the young fish are forced into the main river channel prematurely, where survival rates plummet.

The “Startling” Numbers To understand the gravity of the crisis, we must look at the data rather than just the anecdotes. In the Tuolumne River, fall-run Chinook salmon populations have plummeted from historic highs in the tens of thousands to a fraction of that today. In some recent years, fewer than 1,000 adult fish have returned to spawn. These aren’t just declining numbers; they are signs of an ecosystem on the brink of collapse.

The Core of the Debate: Flows vs. Reliability

To understand the current debate, it helps to look at the three key documents currently on the table at the State Water Resources Control Board:

1. The Scientific Basis Report: This is the State’s official peer-reviewed study. It concluded that the current health of the Bay-Delta is in crisis and that native fish need significantly more water flow to survive.
2. The Bay-Delta Plan: This is the State’s proposed regulatory solution based on that science. It calls for “40% unimpaired flow,” meaning 40% of the water that would naturally flow down the river must remain in the river rather than being diverted.
3. The Tuolumne Voluntary Agreement (TVA): This is the alternative “HRL” (Healthy Rivers and Landscapes) proposal submitted by water agencies. It suggests that we can achieve similar environmental results with less water if we combine modest flow increases with physical habitat projects, like adding spawning gravel.

This is where the friction lies. While water agencies prioritize “design droughts” to ensure safety margins, organizations like the Yosemite Rivers Alliance argue that these scenarios are overly conservative. They point to data suggesting that even under the 40% flow requirements of the Bay-Delta Plan, the regional system could maintain reliability without the “doom and gloom” rationing scenarios often cited.

Environmental advocates also point back to the Scientific Basis Report, noting that the State’s own review found that habitat restoration alone—without the significant flow increases required by the Bay-Delta Plan—would likely fall short of what is needed to recover salmon populations.

Essentially, the State must now decide: Do we follow a mandated percentage of river flow (the Bay-Delta Plan), or do we pivot to a mix of smaller flows and physical habitat projects (the TVA)?

The Uncertainty of Climate Change

Adding another layer of complexity is the unpredictable nature of climate change. Traditional water management relies on historical data to predict future snowpack and weather patterns. However, as climate change makes our weather more volatile, these historical models are becoming less reliable. This uncertainty makes it even harder for water agencies to strike the right balance between conservation and supply.

This challenge is particularly timely for our local leaders. Cities and water districts across California are currently under a state mandate to review and revise their Urban Water Management Plans (UWMPs). By July 2026, these jurisdictions must submit updated assessments that account for more frequent extreme weather events and updated reliability data.

Cities also face challenges in predicting their future water use. As population and development patterns shift, it’s difficult to know exactly how much water will be needed or how residents will respond to potential rationing or restrictions. Many residents are not well-informed about the technical details of water rights or the risks involved in these decisions.

The Housing Collision: 47,000 New Neighbors

The challenge of planning is further complicated by our regional housing goals. Under the Regional Housing Needs Assessment (RHNA), San Mateo County is projected to add approximately 47,700 new housing units by 2031—a 16% increase in our total housing stock.

This creates a massive policy collision. On one hand, the state is mandating significant new housing to solve our affordability crisis. On the other hand, the Bay Delta Plan envisions major reductions in the water available to our region. When cities sit down to write their updated Urban Water Management Plans by July 2026, they must answer a central, difficult question: How do we provide reliable water for 16% more homes while our primary source of water is under threat of being significantly reduced?

Moving Forward: Your Voice in the 2026 Mandate

The C/CAG committee meeting in February made one thing clear: there are no easy answers. The “coequal goals” of ensuring a reliable water supply and restoring the Bay-Delta ecosystem require careful negotiation and a willingness to look at all the data.

As we move forward, it’s essential for the public to stay informed and engaged. Whether you’re a business owner, a resident, or an environmental advocate, your voice matters in this conversation. If you want to have a say in how your community balances these risks, there are two things you can do today:

1. Engage in your city’s July 2026 Mandate: Every city in our county is currently revising its Urban Water Management Plan. These documents determine how much your water will cost and how much you’ll be allowed to use in a drought. Attend your city council’s public hearings on these plans. (You can find a list of San Mateo County city council webpages at bit.ly/SSMC_Advocacy.)
2. Follow the Voluntary Agreement: The state is currently deciding between the Bay-Delta Plan and the “Voluntary Agreement” (TVA) proposed by water agencies. This decision will dictate the health of the Tuolumne River and the reliability of your tap for decades.

Our decisions today will shape the future of our economy and our environment. Whether you are worried about the survival of a keystone species like the salmon or the survival of your local small business, now is the time to get informed and speak up.

Acknowledgements

I would like to express my sincere gratitude to the following individuals for their time, technical expertise and thoughtful review of this article. Their diverse perspectives ensure that this complex topic is presented with accuracy and balance:

• Sean Charpentier, Executive Director, City/County Association of Governments (C/CAG) of San Mateo County
• Donna Colson, Councilmember, City of Burlingame; Chair, C/CAG RMCP Committee
• Peter Drekmeier, Policy Director and Founder, Yosemite Rivers Alliance
• Thomas (Tom) Francis, Water Resources Manager, Bay Area Water Supply & Conservation Agency (BAWSCA)
• Thomas (Tom) Smegal, CEO and General Manager, Bay Area Water Supply & Conservation Agency (BAWSCA)

Follow SSMC Executive Director Sarah Hubbard and SSMC on LinkedIn to see the full series of sustainability articles.